1. Field of the Invention
The present invention relates to an electrical connector with a locking mechanism, and more particularly to an electrical connector with a locking mechanism by which a coupling state with a counter electrical connector is locked by conducting a given rotation operation after the electrical connector is insertedly connected to the counter electrical connector. The present invention relates also to an electrical connector with a locking mechanism in which only a given rotation operation is required for enabling a locking state to be naturally canceled by a spring force.
2. Description of the Prior Art
FIG. 10 diagrammatically shows a prior art electrical connector with a locking mechanism. In the connector C3 of the figure, a cylindrical lock ring 110 is attached to the connector body 100 so as to be longitudinally movable. The connector C3 is insertedly connected to a counter electrical connector C4, and a female thread 111 of the lock ring 110 is then screwed with a male thread 112 formed on the counter electrical connector C4. As a result, the connectors C3 and C4 are locked to each other so as not to drop off.
FIG. 11 diagrammatically shows another prior art electrical connector with a locking mechanism. When the connector C5 of the figure is insertedly connected to a counter electrical connector C6, an engaging piece 210 formed on the connector body 200 is automatically engaged with an engaging portion 220 of the counter electrical connector C6, and the connectors C5 and C6 are locked to each other so as not to drop off. When a pressing portion 230 formed on the connector body 200 is pressed by a finger in the locking state so as to bend inwardly the engaging piece 210, the locking state is canceled and the connector C5 can be extracted from the counter electrical connector C6.
FIG. 12 diagrammatically shows a further prior art electrical connector with a locking mechanism. The connector C7 of the figure has one pole 325. A cylindrical lock ring 310 is attached to the connector body 300 of the connector C7 so as to be rotatable and axially movable. The lock ring 310 is always urged toward the illustrated initial position in the retracting direction, by a spring member (not shown) which is interposed between the connector body 300 and the lock ring 310. A slot 320 which elongates in the spiral direction is opened in the lock ring 310. An engaging holding face 322 is sectionally formed in the hole wall face 321 of the slot 320. When the connector C7 is insertedly connected to a counter electrical connector C8 and the lock ring 310 is then rotated, the entire wall face 321 of the slot 320 is engaged with an outward projection 324 disposed on the counter electrical connector C8, so that the lock ring 310 is moved forward, whereby the outward projection 324 is engaged with the engaging holding face 322, with the result that the connectors C7 and C8 are locked to each other so as not to drop off. When the lock ring 310 in the locking state is reversely rotated, the locking state is naturally canceled by the spring force and the connector C7 can be extracted from the counter electrical connector C8.
Among the above-described prior art connectors C3, C5, and C7 of FIGS. 10, 11, and 12, the connector C7 of FIG. 12 has excellent locking operability because a locking operation can be completed only by insertedly connecting the connector to the counter electrical connector C8 and then slightly rotating the lock ring 310. Furthermore, the connector C7 has an advantage that, when the outward projection 324 of the counter electrical connector C8 and the slot 320 of the lock ring 310 of the connector C7 are formed in two places which are separated from each other by 180.degree., high locking stability is obtained wherein an offset load hardly occurs.
In the connector C7 of FIG. 12, in the case where the connector has a single pole 325 as illustrated, even when the lock ring 310 at its initial position is rotatable with respect to the connector body 300, the locking operation can be conducted by insertedly connecting the connectors C7 and C8 to each other at a position where the outward projection 324 of the counter electrical connector C8 can be fitted into the slot 320 of the lock ring 310, and then rotating the lock ring 310. In the case where the connector C7 is a multipolar connector having plural poles, when the connectors C7 and C8 are to be insertedly connected to each other, it is required to conduct a two-step positioning operation in which the fitting positions in the peripheral direction of the connectors are first determined in order to enable the poles (not shown) of the connectors to be adequately connected to each other, and the lock ring 310 is then rotated so as to adjust the position of the slot 320 in the peripheral direction to the position where the outward projection 324 of the counter electrical connector CB can be fitted into the slot. This prevents the connection work from being conducted rapidly and smoothly.